△I don't konw his occupation.
◎I don't know what he does.
△My destination has not decided.
◎I don't know where I'm going to go.
⇒ I don't know what they are going to say.
⇒ They don't know who did it.
Tell me when you are going to come.
It doesn't matter when you come.
What you're saying is interesting.
What happened happened.
Where we go is up to you.
Whoever did it should be honest.